V. ON TWO ABNORMAL SPECIMENS OF DUCKS IN 



THE COLLECTION OF THE ZOOLOGICAL 



SURVEY OF INDIA. 



By Herbert C. Kobinson, M.jB.O.U. 



Amongst some six hundred duck shot on a swamp near Pathshala iu 

 Assam, near the Bhutan Hills, in April, 1917 by Mr. A. Milton were two 

 somewhat uncommon specimens which were presented by him to the 

 Indian Museum. 



One of these (25450, Z.S.I.) is a typical male Gadwall Chaulelasmus 

 streperus (Linn.) and calls for no special remark. 



The other (25451, Z. S. I.), also a male, caused me some consider- 

 able trouble in its identification, and until recently I was inclined to 

 consider it as a hybrid between the Common Mallard Anas boschas, 

 (Linn.) and the Gadwall Chaulelaswus streperus (Linn.). 



Comparison of the specimen with other skins and further consulta- 

 tion of the literature has convinced me that I was in error in this iden- 

 tification and that the bird is a hybrid between Eunetta falcata (Georgi) 

 and Chaulelasmus streperus (Linn.), in which the characters of the first 

 mentioned species are dominant. 



The bird is not in full plumage and the highly elongate occipital 

 feathers and strongly decurved and gickle-shaped tertiaries characteristic 

 of the fully adult male Falcated Teal are not strongly in evidence. 

 The following is a full description of the bird : — 

 Tail, apparently of sixteen and not fourteen feathers, therein agree- 

 ing with Chaulelasmus and not Eunetta. Upper and lower tail coverts 

 as long as rectrices. Occipital feathers produced, forming a slight 

 " mane." 



Anterior lores and an ill-defined frontal patch and a small subocular 

 spot dirty white ; top of the head dull chestnut, sides of the head and 

 occipital mane bronzy green, the feathers faintly tipped with whitish ; 

 chin, throat and an interrupted collar white, narrowly bordered above 

 with blackish ; a broad bronze green collar succeeded by a narrower 

 white one, interrupted behind. 



Mantle, hind-neck and breast with broad V-shaped vermiculations of 

 white and brownish-black, with a bronzy tint, the white element narrow- 

 est. Scapulars and flanks the same, but the vermiculations finer and 

 straighter. A black spot on the outer webs of the outer elongated 

 scapulars. Upper back brownish, faintly vermiculated with white, 

 lower back and upper tail coverts black. 



Tail feathers greyish above, whitish beneath, the outer webs with 

 dark edges. Under tail coverts black, the outermost with a large median 

 spot of buff. Belly whitish, finely vermiculated with greyish-black. 



Lesser wing coverts dove grey, the innermost vermiculated with 

 whitish ; median coverts grey, the median portion of each feather 

 whitish with the tips of the outer webs broadly chestnut, forming a 

 ■double wing bar. Outer secondaries black on their outer webs, the inner 



